Network News Transfer Protocol (NNTP) is the underlying protocol of UseNet, which is a worldwide discussion system which contains posts or articles which are known as news. Network News Transfer Protocol is used to transfer news from one network to another. It is designed specifically to transfer news/articles. A NNTP client is included in browsers like Netscape, Opera and Internet Explorer or a special application named newsreader can be used as a NNTP client. NNTP servers manages the global network of news groups.
Usenet originally used the Unix to Unix Copy Protocol (UUCP). In this protocol, servers copied all news on their local disks, posters and readers logged in to these servers to access articles directly from the local disk. It was necessary to make UseNet accessible for personal computers with increase in use of the Internet. Hence NNTP was designed on similar lines to that of Simple Mail Transfer Protocol (SMTP). It was made by multiple contributors which included Brain Kantor, Phil Lapsley, Sant.O.Barber, Erik Fair. Brain Kantor and Phil Lapsley wrote the RFC 977, “Network News Transfer Protocol” in March 1986.
NNTP is a set of rules for clients/newsreaders to interact with servers to retrieve newsgroups. NNTP client communicates with a server using commands like “ARTICLE” to retrieve an article or “NEWS” to retrieve a whole newsgroup etc. Mostly these commands are interpreted directly by newsreader software which sends and receives signals from the servers.
Port 563 or 119 is used by NNTP clients/newsreaders. Post 433 is used by Servers hence it is also called NNSP.
The newsgroups are hosted by multiple servers. The servers in this distributed network are simple peers which have information about other peers with whom they share articles. A new article is added to a server, the server periodically sends added articles to it’s peer servers. A server need not store all the newsgroups on the network, it can choose which newsgroups it will store, provided it’s peer has those newsgroups.And if the peer doesn’t, then it can find new peers which have those newsgroups.Anyone can setup personal newsgroups using softwares like Apache James and Leaf node.